The Food and Drug Administration (F.D.A.) defines an empty stomach as “one hour before eating, or two hours after eating.” [1]https://www.fda.gov/home
On average it takes about 2 to 4 hours for food to move from your stomach to your small intestine. Food can spend between 2 to 6 hours in your small intestine before goes to the large intestine. In your large intestine, the waste products from your food spend around another 36 hours here. [2]https://www.healthline.com/health/how-long-does-it-take-for-your-stomach-to-empty#what-affects-this